Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
You would be installing Mac OS X rather than iOS, and it's not a particularly easy task. In fact, that computer may not even run it at all, as OS X does not have support for every CPU and GPU on the market. So if you plan to run it as a Mac, I wouldn't buy it. If you really want to run a custom tower as a Mac, it's best to build it yourself, but it does take a good bit of research and a lot of maintenance. If you want a Mac, it is by far the easiest to simply buy a Mac, although not the least expensive.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.